A conventional biped walking humanoid robot generates the pre-designed walk pattern (hereinafter to be called “gait”) data, conducts walk control according to the gait data, moves leg portions by the pre-designed walk pattern, and thereby realizes biped walking. Here, in order to stabilize walk posture, stabilization of the robot is targeted by ZMP regulation by what is called ZMP Compensation, whereby a point on the sole of a foot of the robot where the composite momentum of floor reaction force and gravity becomes zero is converged to the target value.
Incidentally as a biped walking humanoid robot's motions, in addition to walking, uprising motion without walking, so-called rotational motions to change direction, or stand up motion from sitting posture on a chair, and others can be mentioned. In order to realize a more practical humanoid robot, such various motions have to be conducted quickly and smoothly.
However, such motions are designed to be conducted independently of one another, and, in case respective motions are conducted in series, they are not continuous and smooth in general. Especially, continuation of quick motions tends to cause the robot's tumbling down due to unbalancing caused by inertial force generated from respective motions. For this reason, conventional biped walking humanoid robots are controlled, after one motion is completed, to stop once, and slowly move to another motion, thereby their motions look quite mechanical.
Further conventional biped walking humanoid robot are in many cases operated by an operator with outside control system for convenience and real time motions, for which menu display, operation buttons, or joysticks are provided to the control system for choosing motion, and the motion for the robot to conduct is chosen by using said parts. Therefore, when the operator chooses next motion for the robot to conduct and the robot conducts the chosen next motion, the robot may tumble down by unbalancing, or the drive means to drive its each part may be overloaded by unnatural posture. Thus, it has so far been difficult for a biped walking humanoid robot to conduct various motions continually and smoothly.